Electric-lamp-socket fastening.



H. GHRISTENSEN.-

ELEGTRIG LAM1 SOGKET FASTENING.

APPLICATION IILBD D30. 3 1908.

9 38,2 1 2. Patented Oct. 26, 1909.

HJALMAR CHRISTENSEN, OIE SEATTLE, WASHINGTON.

ELECTRIC-LAMP-SOCKET FASTENNG.

Specification of Letters Patent.

Patented Oct. 26, 1909.

Application filed December 3, 1908. Serial No. 465,882.

T0 all whom t't may concem:

Be it known that I, HJALMAR CHRISTEN- SEN, a citizen of the UnitedStates of America, and a resident of the city of Seattle, in the countyof King and State of Washington, have invented certain new and usefulImprovements in Electric Lamp Socket F astenings, of which the followingis a specification.

My invention relates to devices of the above type and has for one of itsobjects the provision of an improved construction, through the medium ofwhich lamp sockets can be firmly and securely held in position.

A further object resides in the provision of a fastener which, asrotated to secure the lamp socket in position, takes a firm hold on thelamp socket, so as to be held against accidental backward turning uponjarring of the sign board or other support for the lamp socket.

With the above and other objects in view, to be referred to, as mydescription progresses, my invention resides in the structural fcatures,arrangements and combinations of parts hereinafter described andsuccintly defined in my annexed claims.

Referring now to the accompanying drawing wherein I have illustrated apreferred embodiment of my invention: Figure 1 is a side view partly insection, of a lamp socket secured in position. Fig. 2 is a fragmentaryview in side elevation of the lamp socket removed. Fig. 3 is a view inside elevation of the securing ring, and Fig. 4 is a rear end viewthereof.

In carrying out my invention I provide a lamp socket, 1, with anexternal shoulder 2 which, in the present application of my invention isadapted to be disposed at the forward side of the sign board 3, througha suitable opening in which the socket projects, as clearly shown inFig. 1. Shoulder 2 can obviously'be formed in any desired manner toprevent the socket slipping rearwardly through the opening in the signboard and as found desirable an elastic ring, as 4, or other fillermember having elastic properties, can be arranged between it and theadjacent face of the sign board 3. Rearwardly of shoulder 2, socketmember 1 has an external rearwardly tapering portion 5, which issubstantially frusto -conical in form, on which a .clamping member 6 ofring form is adapted to be rotatably supported. This tapered portion 5extends rearwardly t0 a shoulder 7 which by its angular dispositionprovides a cam surface adapted to be engaged by the clamping member 6,and upon rotation of the latter compel the same t0 advance and bearagainst the rear face of the sign board.

The internal face of clamping member 6 is tapered in conformity with thetapercd portion 5 of the socket member 1, and consequently member 6 intraveling forwardly thereon in moving to a clamping position, as justdescribed, Will bind thereon for its entire length and Ioe therebyfrictionally held against accidental backward turning.

In order to obtain a comparatively great adjustment of clamping member6, shoulder 7 is extended in a spiral path for one coniplete turn. Thelength of shoulder 7 can, however, be decreased or increased withoutdeparting from the spirit of my invention.

Clamping member 6, as now considered, has' its rear edge shaped toconform to the curvature of shoulder 7 and is preferably split so thatit can be expanded and slipped onto and ofi' of the socket over the rearend portion thereof. At its forward edge member 6 is provided with anoutwardly projecting flange 8, which provides a broad .engaging orclamping portion arranged to coact With shoulder 2, to obtain a firmgrip on the sign board.

T0 prevent expansion of member 6, a tongue 9 is provided on one freeedge portion thereof and this in operation is passed through a slot 10,formed in the other end portion of said member, then bent back asillustrated in Fig. 1.

Various changes may be made in the details of construction, withoutdeparting from the spirit of my invention as defined in my annexedclaims.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is:

1. An annular clamping member for cloctric lamp sockets, the interior ofwhich is substantially frusto conical in form, one side edge of saidclamping member being formed into a cam surface.

2. An electric lamp socket formed with external shoulders spaced fortheir entire lengths, and a clamping ring engaged with one of saidshoulders and being free to be rotated on the socket, and means forefiecting a lengthwise shifting of said ring during rotation thereof,the shoulder engaged by said rin being arranged entirely to the rearthereo 3. An electric lamp socket formed with spaced external shoulders,and a clamping member seated on said lamp socket between the shouldersthereof and being free from the surface of said socket for endwsesliding thereon between said shoulders thereof, said clamping memberhaving a cam portion engaged with one of the shoulders of said Socketfor efiecting lengthwise s1iding of the clamping member during rotarymovement thereof.

4. In combination with a sign board formed with an opening, an electriclamp socket projecting through the opening of sad sign board andprovided with spaced shoulders, one of Which bears againsc one face ofsaid Sign b0ard and the other being spaced from the other face of saidsgn board and provided With a cam face extending in a spiral path, and aclampng ring seated directly on said socket entireIy between said lastnamed shoulder and the adj acent face of said sign board.

Signed at Seattle, Washington this 27th day of November 1908.

HJALMAR CHRISTENSEN.

Witnesses:

A. A. BOOTH, FRANK E. ADAMS.

